Pius I

Pope Pius I served as Bishop of Rome from approximately 140 to 154, making him one of the earliest popes about whom more than a name survives. The Muratorian Canon and the Liberian Catalogue both identify him as the brother of Hermas, author of The Shepherd of Hermas — a text so widely read in the second century that some early Christians treated it as scripture. Hermas identifies himself as a former slave, leading to the reasonable conjecture that both he and Pius came from a freedman background, though this remains uncertain. His pontificate fell during the reigns of Emperors Antoninus Pius and Marcus Aurelius, a period of relative peace for Rome but intense theological ferment within the Church. Three significant heretics visited Rome in his time: Valentinus, who taught an elaborate cosmological dualism; Cerdon, who preceded Marcion in rejecting the God of the Old Testament; and Marcion himself, who built a rival church and canon. Pius is believed to have confronted and excommunicated these groups — a fact Catholic apologists have cited as evidence for Roman primacy already in the second century. Justin Martyr taught Christian doctrine in Rome during Pius's pontificate, providing a glimpse of the intellectual vitality of the Roman church at this time. The two were contemporaries, though no document records a direct exchange between them. Pius is traditionally credited with decreeing that Easter must be celebrated on a Sunday rather than on the fixed fourteenth of Nisan in the Jewish calendar. This ruling did not immediately settle the question — the Quartodeciman controversy continued to divide Rome from Eastern churches for generations — but it established the trajectory of Western practice. He is also credited with building the church of Santa Pudenziana on the Esquiline Hill, one of the oldest Christian places of worship in Rome. Earlier editions of the Roman Breviary listed him as a martyr, but the 1969 revision of the General Roman Calendar concluded there were no historical grounds for this, and the current Roman Martyrology does not present him as one.